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Isaac Newton discovered the basic techiques of the differential and integral calculus, and applied them in the study of many problems in mathematical physics. His main methematical works are the \emph{Principia} and the \emph{Optics}. He summed up his own estimate of his work as follows:

\begin{quote}
  I do not know what I may appear to the world; but to myself I seem to have been only like a boy, playing on the sea-shore, and diverting myself, in now and then finding a smoother pebble, or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
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\begin{quotation}
  I do not know what I may appear to the world; but to myself I seem to have been only like a boy, playing on the sea-shore, and diverting myself, in now and then finding a smoother pebble, or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.

  I do not know what I may appear to the world; but to myself I seem to have been only like a boy, playing on the sea-shore, and diverting myself, in now and then finding a smoother pebble, or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
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In later years Newton became embroiled in a bitter priority dispute with Leibniz over the discovery of the basic techniques of calculus.

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